So, to use your keyboard with MIDI in and out, you need a soundcard with MIDI connectors.
An internal PC soundcard with MIDI connectors is M-Audio Audiophile 192. I had one on my old computer and never had a problem with it.
An external soundcard wih MIDI connectors is Focusrite Scarlett 18i6, which I use right now.
If those are a bit too pricy, then you can get a usb adapter like this:
http://www.zzounds.com/cat--USB-MIDI-Interfaces--2434